United States securities and exchange commission logo July 31, 2020 Brian L. MacNeal Chief Financial Officer Armstrong World Industries, Inc. 2500 Columbia Avenue Lancaster, Pennsylvania 17603 Re: Armstrong World Industries, Inc. Form 10-K for the Year Ended December 31, 2019 File No. 001-02116 Dear Mr. MacNeal: We have completed our review of your filing. We remind you that the company and its management are responsible for the accuracy and adequacy of their disclosures, notwithstanding any review, comments, action or absence of action by the staff. Sincerely, Division of Corporation Finance Office of Manufacturing